Background/Objectives: Vitamin C intake has been inversely associated with breast cancer risk in case–control studies, but not in meta-analyses of cohort studies using Food Frequency Questionnaires, which can over-report fruit and vegetable intake, the main source of vitamin C. This is the first study to investigate associations between vitamin C intake and breast cancer risk using food diaries.

Conclusions: This pooled analysis of individual UK women found no evidence of significant associations between breast cancer incidence and dietary or total vitamin C intake derived uniquely from detailed diary recordings.

Acknowledgements.The UK Dietary Cohort Consortium is part of the MRC Centre for Nutritional Epidemiology in Cancer Prevention and Survival which is funded by the Medical Research Council. The cohorts forming the consortium have received funding from the World Cancer Research Fund, Cancer Research UK, the British Heart Foundation and the Medical Research Council. Professor Sheila Rodwell (also known professionally as Sheila Bingham), who died in 2009, established the UK Dietary Cohort Consortium as part of the MRC Centre for Nutritional Epidemiology in Cancer Prevention and Survival, of which she was director.